New scripts for create/drop user/db from Peter Eisentraut

doc/src/sgml/Makefile

doc/src/sgml/docguide.sgml

doc/src/sgml/ref/allfiles.sgml

doc/src/sgml/ref/commands.sgml

doc/src/sgml/ref/create_database.sgml

doc/src/sgml/ref/create_user.sgml

doc/src/sgml/ref/createdb.sgml

doc/src/sgml/ref/createlang.sgml

doc/src/sgml/ref/createuser.sgml

doc/src/sgml/ref/destroydb.sgml

doc/src/sgml/ref/destroylang.sgml

doc/src/sgml/ref/destroyuser.sgml

doc/src/sgml/ref/drop_database.sgml

doc/src/sgml/ref/drop_user.sgml

doc/src/sgml/ref/dropdb.sgml

doc/src/sgml/ref/dropuser.sgml

src/bin/Makefile

src/bin/createdb/createdb.sh

src/bin/createuser/Makefile

src/bin/createuser/createuser.sh